Device for elevators.



R. L. GARNETT.

DEVICE FOR ELEVATORS.

APPLICATION FILED MAY 19, 1909.

952,988. Patented Mar.22, 1910.

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R. L. GARNETT.

DEVICE FOR ELEVATORS.

APPLICATION nun) MAY 10. 1009.

Patented Mar. 22, 1910,

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ROBERT L. GARNETT, OF CEDAR FALLS, IOWA.

DEVICE FOR ELEVATORS.

Specification of Letters Patent.

Patented Mar. 22, 1910.

Application filed May 19, 1909. Serial No. 497,017.

To all whom it may concern:

Be it known that I, ROBERT L. GARNETT, a citizen of the United States,residing at Cedar Falls, in the county of Blackhawk and State of Iowa,have invented new and useful Improvements in Devices for Elevators, ofwhich the following is a specification.

The invention relates to a safety device for elevators, and moreparticularly to the class of automatic safety devices for elevators,dumb waiters, or the like.

The primary object of the invention is the provision of a safety devicein which an elevator cage or lift is brought to a stop, either inascending or descending upon the breaking of its lifting cable or otherhoisting medium,.thus assuring safety to its load, whether the same bepersons or freight.

Another object of the invention is the provision of a safety device forelevators or the like, in which its car or cage is assured againstsudden dropping in the shaft or well where it travels, while ascendingor descending, and may be automatically stopped upon the fracture orbreakage of the lifting means of the said car or cage while in motion.

A further object of the invention is the provision of a safety device ofthis character, which is simple in construction, readil and easilymounted upon a cage or car of an elevator, thoroughly reliable andefficient in its operation when in use, and inexpensive in themanufacture.

In the drawings accompanying and forming part of this specification isillustrated the preferred form of embodiment of the invention, which toenable those skilled in the art to practice the invention, will be setforth at length in the following description while the novelty of theinvention will be brought out in the claim succeeding the description.

However it is to be understood that changes, variations andmodifications may be made, such as come properly within the scope of theappended claim, without departing from the spirit of the invention.

In the drawings:Figure 1 is a fragmentary side elevation of one standardof an elevator cage and its guide rail, with the invention applied andin an inoperative position. Fig. 2 is a sectional view on the line 2-2of Fig. 1. Fig. 3 is one end elevation.' Fig. 4 is a longitudinalsectional view with the parts shown in dotted lines when in operativeposition.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

In the drawings the numeral 5 designates a side vertical bar or standardof an eleva tor car or cage, it being understood of course that thelatter is of ordinary well known construction and in ascending anddescending is adapted to travel on guide rails or tracks, one of whichin this instance is shown and designated by the numeral 6, the same alsobeingof the usual type. At any suitable locality upon the bar orstandard 5, is mounted a casting forming a supporting plate 7 providedwith spaced engaging flanges 8, projecting at right angles to its innerface to partially surround the said standard or bar and being securedthereto by suitable fasteners 9, passin through the latter and the saidflanges. 6n the opposite outer face of the supporting plate 7 are spacedparallel guide flanges 10, the same receiving therebetween the guiderail or track 6, 1n the ascending or descending of an elevator cage orcar. Formed on one of the flanges 10, and in spaced parallel relation tothe supporting plate 7 is a shield or housing plate 11, between whichand the said plate 7, is mounted an eccentric gripping member having aWheel or roller 12, rotatably journaled eccentrically upon a bolt 13,forming its axis secured in any suitable manner transversely in thecasting, and this eccentric member is adapted for automatic frictionalgripping engagement with the guide rail or track 6, for the purpose aswill be hereinafter described.

Integral with the eccentric member is an arm or lever 14, to the outerfree end of which is connected one end of a retractile spring 15, whichhas its opposite end connected to a perforated ear 16, fixed to thestandard or bar below the casting and by means of this spring 15, theeccentric memher is thrown into action or automatically into engagementwith the guide rail or track for the stopping of the elevator car orcage.

Connected between the plates 7 and 11 is a trip device by means of apivot 17, above the path of movement of the arm or lever 14, and thistrip device comprises an inverted Ushaped yoke or loop 18, adapted toengage a nose 19 offset from the upper edge of the lever or .armylet,toihold the eccentric member in normal inoperative position. Extendingfrom one side of the loop or yoke 18, is a trip arm 20, and at adistance removed therefrom upon the casting on a pin.

, 22 will be supported upon the pin '28 by gravity so as to pass thetrip arm 20 without engaging the latter when the pulley 21 rotates atnormal or slow speed.

' Trained over the pulley 21, is a rope or cord 24, the upper end beingsecured at any desirable point in the elevator shaft or well and itsopposite end has connected thereto a weight 25, so as to hold the ropeor cord taut about the pulley and to effect the travel of the same overthe latter and also to maintain a uniform speed of rotation to saidpulley when the elevator .cage or car is ascending or descending in ashaft or well under normal conditions and in this manner the strikermember or dog will be normally held out of the path of the trip arm vofthe trip device.

' In operation and presuming that the lifting cable .or medium of theelevator car or cage suddenly becomes broken during the descent of thelatter or when for any reason the descent is at an abnormal or unusualrate of speed, the pulley 21 will be caused to rotate in excess of itsnormal speed by the rope or cord 24, traveling thereover at itsperiphery and by centrifugal action the striker member or dog will beswung outward into the path of the trip arm thus releasing the trippingdevice to free the lever or arm of the eccentric member and by theretractile spring this latter gripping mem- ,ber will be automaticallyoperated to fricand its guide of a spring actuated cam lever pivoted onthe cage and adapted :to engage the guide, said cam lever being providedwith a projecting lug on its upper edge, a pivotal ly supported yokeengaging said lug and holding the lever out of gripping engagement withthe guide against the tension of the actuating spring, said yoke beingprovided with a laterally extending trip arm, a pulley supported forrotation, a pin upon the face of the pulley, a dog supported pivotallyupon the face of the pulley, and adapted to vibrate between the pin andthe supporting shaft of the pulley, said dog con stituting a strikeradapted to engage the laterally extending arm of the trip yoke, and arelatively immovable cable frictionally engaging the pulley ,to'rotatethe same.

In testimony whereof I affix my signature in presence of two witnesses.

I ROBERT L. :GARNETT.

lVitnesses:

FRANK MIHM, GEORGE H. SeHULzn.

